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The percentage of doping in emitter is higher than collector region.hence large current is flow to emitter than collector.
What else can I help you with?
IS Emitter base resistance greater than emitter collector resistance in transistor?
It depends on whether the transistor is in the active region or not. Usually, the transistor would be in the active region when we are asking this question. if we look at the data sheet for the popular 2N3905 transistor, available at http://www.fairchildsemi.com/ds/2N/2N3905.pdf, we see that if V collector-emitter is 10 V, the collector current is 1 mA, and the small signal frequency is 1 kHz, the typical small signal signal input impedance (which is nearly the same as small signal base-emitter resistance) is about 5,000 ohms. Under the same conditions, the typical output admittance, (which is nearly the same as the small signal collector-emitter resistance) is about 30 microsiemens. Calculate 1/0.000030 to find that this is the same as about 33,000 ohms, so in this case the collector-emitter small signal resistance is greater than the base-emitter small signal resistance. You might be able to find an operating point where the reverse is true.
Why name of the device is UJT?
UJT means Uni Junction transistor terminals are Emitter,Base1 and Base2.UJT is also called double base diode.UJT operates when the emitter is forward biased.voltage is applied between base1 and base2.If an external voltage is applied at terminal E,no current will flow in to the emitter as long as this applied voltage is less than emitter voltage.When this applied voltage exceeds emitter voltage,current will flow into the emitter and holes get injected from emitter to base1 and are repelled by base2.This results in increase in the region between the junction and the base 1.The increase in conductivity results drop in emitter voltage and increased forward bias of the junction.so emitter current also increases.Then it exhibits a negative resistance.
How do you identify a pnp or npn transistor?
If you know the base of the transistor, and you have an ohmmeter that puts out more than about 0.7 volts, you can check base to emitter or base to collector as if it were a diode, and it will conduct when the more positive lead of the ohmmeter is connected to the P junction. That will tell you if the transistor is NPN or PNP. If you don't know the base, you can check all six directions. Only two should conduct, the two that are forward biased towards the base.
How do you design a bjt amplifier with gain 10?
To design a bjt amplifier with gain 10, consider that gain in a class A common emitter configuration is collector resistance divided by emitter resistance. So, pick the two resistors so that their ratio is ten. Bias the base so that the collector is at the center of the operating voltage range, along with the transistor being at the center of its linear region. Of course, you need to consider impedance and operating current, so you need to choose carefully. Also, the beta (hFe) of the transistor must be substantially more than ten for this to work reliably. Often, this voltage gain stage is followed by a class C common collector emitter follower to give you current gain as well.
Why use a npn transistor in a common emitter bjt single stage amplifier circuit?
You can use an npn or a pnp bjt in a common emitter amplifier circuit. The decision of which one to use is based on whether you want the collector and base to be more positive (npn) or more negative (pnp) than the emitter.
Why is collector current slightly less than emitter?
The percentage of doping in emitter is higher than collector region.hence large current is flow to emitter than collector.
Why is collector slightly less than emitter?
some of emitter current goes out base instead of collector
Why is collector current increased slowly with the increase of collector to emitter voltage of a common emitter?
The percentage of doping in emitter is higher than collector region.hence large current is flow to emitter than collector.
Why the base current in the transistor is so much less than the collector?
as the base current is very small compared to the emitter current,the collector current is nearly equal to the emitter current..
Why is the base current in a transistor so much less than the collector current?
as the base current is very small compared to the emitter current,the collector current is nearly equal to the emitter current..
Why output of common emitter amplifier is inverted?
In a common emitter amplifier, the base-emitter current causes a corresponding collector-emitter current, in the ratio of hFe (beta gain) or collector resistance over emitter resistance, which ever is less. Since this ratio is usually greater than one, the differential collector current is greater than the differential base current. This results in amplification of the base signal. As you increase the base-emitter current, the collector-emitter current also increases. This results in the collector being pulled towards the emitter, with the result that the differential collector voltage decreases. This results in inversion of the base signal.
What should be the value of collector current in terms of DC gain if transistor is in saturation mode?
DC current gain is collector-emitter current divided by base-emitter current. In linear mode, gain is beta, or hFe. In saturation mode, however, the transistor is over-driven and you can no longer relate collector-emitter current to base-emitter current. The transistor operates like a switch, and collector-emitter current is a function of voltage and load impedance only. (Ignoring the relatively small voltage drop.) To maintain saturation mode, the collector-emitter current must be smaller than the base-emitter current times hFe. Often, it is several times smaller, because hFe can vary from transistor to transistor, and your design must account for this variability.
What is the difference between a transistor used as a switch and an amplifier?
A transistor used as a switch is operated in saturated mode, where the ratio of base-emitter current over collector-emitter current is far more than hFe, or beta gain. The transistor is either fully on or fully off in this mode. A transistor used as an amplifier is operated in linear mode, where the ratio of base-emitter current over collector-emitter current is equal to or less than hFe, or beta gain. The transistor is partially on in this mode, and is operating as a current controlled current sink.
What are the characteristics of a CB amplifier?
it is a mode of amplifier connection where the base part of the transistor is made common to both input and output.the circuit diagram is as shown below. the transiator gain(represented by the greek letter beta-B) is usually evaluated by the formula B=output current divided by input current. as we know that when the transistor is connected in common base mode the input pert will be emitter and the output part will be collector and we know that the collector current is quiet less than emitter current. as per the formula gain will be less than one. practically we consider emitter current as equal to collector current and hence B approaches 1 in case of common base mode amplifiers.as the gain is very less it is very less used as amplifiers. generally they use common emitter mode for amplification as this mode optimum amount of amplification.
What will happen to voltage divider circuit if emitter resistance is greater than collector resistance?
The gain of a class A, common emitter BJT amplifier, a fairly standard configuration, is defined as collector resistance divided by emitter resistance, or as hFe, whichever is less. Assuming that we are operating in a linear mode, and hFe is not a limiting factor, then the emitter resistance being greater than the collector resistance simply means that the gain is less than one.
What are the bias condition of the base emitter and base collector junction for a transistor to operate as a switch?
In order for a transistor to operate as a switch, the base-emitter current must be greater than the collector-emitter current divided by a factor of hFe. In this state, the transistor operates in saturated mode, fully turning on.
What are the bias conditions of the base emitter and base collector junction for a transistor to operate as a switch?
In order for a transistor to operate as a switch, the base-emitter current must be greater than the collector-emitter current divided by a factor of hFe. In this state, the transistor operates in saturated mode, fully turning on.
